Pneumatic deicer periphery bleeder

ABSTRACT

A pneumatic deicer having passages for inflation and deflation to break up ice accumulations on the surface with a bleeder channel in the trailing edge containing a plurality of stiff fibers extending from one face of the channel toward the other to hold the channel open for maximum flow of the inflating medium out of the passages and thereby provide the rapid deflation needed for effective breakage of the ice forming on the surface.

United States Patent Roemke PNEUMATIC DEICER PERIPHERY BLEEDER [72] Inventor: Lowell W. Roemke, 231 Sharon- Copley Rd.-R.F.D. l, Wadsworth,

Ohio 44281 [22] Filed: Sept. 23, 1970 [2l] Appl. No.: 74,690

[52] US. Cl. ..244/l34 A [51] Int. Cl. ..B64d 15/16 [58] Field of Search ..244/134 R, 134 A [56] References Cited UNITED STATES PATENTS 3,370,814 2/1968 Kageorge et al. ..244/ 134 A 2,957,662 10/1960 Hess .244/l34 R [451 Sept. 12, 1972 Antonson ..244/1 34 A Hunter et al ..244/] 34 A Primary Examiner-Milton Buchller Assistant Examiner-Gregory W. O'Connor Attorney-John D. Haney and Harold S. Meyer [5 7] ABSTRACT 4 Claims, 4 Drawing Figures PATENTEDSEP 2 Ian m i 5W m v ow Q 3 F 2 INVEMOR. r LOWELL WROEMKI PNEUMATIC DEICERPERIPHERY BLEEDER BACKGROUND OF THE INVENTION This invention relates to pneumatic deicers of the type in which a boot of resilient material such as rubber is attached to the leading edgeof an airfoil and has a series of inflatable passages which are alternately extended by inflation pressure to break up ice accumulation which tends to form on the surface of the boot exposed to the air flow. The passages are deflated by releasing the inflating medium from the boot and the deicer is maintained in the deflated condition while a layer of ice is built up on the surface. The deicer is then inflated again to shatter the layer of ice whereupon the broken ice particles are blown off by the airstream across the airfoil.

To obtain maximum efficiency, it is desirable to keep the time interval required for inflation and deflation to a minimum. With somedeicer constructions, the length of the boot and the satisfactory positions of the air inlet port have been seriously restricted to obtain this efficiency,.Asa general rule, the longer the distance SUMMARY OF THE INVENTION The pneumatic deicer of this invention provides a boot which is constructed to greatly reduce. the time required for inflation and deflation. This is accomplished byproviding for rapid deflation of the boot through a special bleeder channel located along the trailing edge of the deicer. The bleeder channel contains a strip of material having a large number of stiff fibers extending from the strip to an opposing face of the bleeder channel which holds the channel open for maximum flow of the inflating medium out of the passages in the deicer boot. It has been found that the use of this construction permits placement of the air inlet port in many different positions and has permitted greater distances between the air inlet port and the ends of the deicers as compared with previous designs.

This construction is superior to the alternative of using an outer fabric of greater elasticity which increases the weight and cost of the deicer and detracts from its appearance and aerodynamic efficiency. It is also superior to the other expedient of adding more air outlets which increases the cost of the boot as well as the installation and maintenance.

The accompanying drawings show one preferred form of deicer boot made in accordance with and embodying this invention and which is representative of how this invention may be practiced.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

DETAILEDDESCRIPTION A laminated, inflatable deicer boot 10 is shownin FIG. 1 in the condition prior to installation on an airfoil with the leading edge of the airfoil to be covered .bythe leading edge portion of the boot indicated by'the dotdash line L-L. Trailing edges 11 and 12 of the boot are parallel to the leading edge portion LL and extend to the rear of the airfoil on the upper and under side thereoffAs shown in FIGS. 1 and 2, the bottom ply 13 which may be of fabric coated. with rubber-or other resilient rubberlike material, extends under the deicer boot 10 and is fastened to the airfoil by suitable means well known in the art and not shown in this application. Atop ply 14 which may be of fabric coated with rubber or other resilient rubberlike material overlies the bottom ply l3 and is covered by a sheet member 15 of resilient rubberlike materialsuch as neoprene which covers the deicer boot on the external airflow side. Between the top ply 14 and bottom ply 13 is an intermediate member 16 which may be of fiber glass or other reinforcing material.

In this preferred construction, the bottom ply 13, top ply 14 and intermediate member 16 are sewed together by a series of stitches 17 so thata series of parallel passages 18 are formed lengthwise along the boot as shown in FIG 1 by dotted lines.

A peripheral bleeder channel 19 is located in the trailing edge 11 of the deicer boot and is in communication with the passages 18 in the space between the top ply 14 and intermediate member 16. Channel 19 extends along the trailing edge 11 in a longitudinal direction from one end of the deicer boot 10 to the other end in parallel relationship to the passages 18. Where there is an access opening 22 in the deicer boot 10, bleeder channel 19 extends along the trailing edge 11 past the opening to provide a continuous channel from one end of the deicer boot to the other. This construction is shown in detail in FIG. 3.

The bleeder channel 19 contains a fabric strip 23 having a plurality of closely spaced elements such as stiff fibers 24 which project from the upper surface of the channel downwardly to the opposing lower surface of the channel to provide interstices through which the inflating medium can flow. A fabric reinforcing member 25 extends between the sheet member 15 and top ply 14 over the strip of fabric 23 and along the side of the channel 19 and then into the trailing edge 11 where it is embedded in the resilient rubberlike material of the boot 10. As shown in FIG. 3, the fabric reinforcing member 25extends along the top and both sides of the bleeder channel 19 andthen is embedded in and adhered to the resilient rubberlike material of the deicer boot on both sides of the channel where there are no passages 18 as in the area of the access opening 22.

A second channel like bleeder channel 19 in the trailing edge 11 may also be built into the trailing edge 12 to provide improved flow of the inflating medium out of the passages 18. Air inlet and outlet opening 26 may be located in a convenient spot for maintenance and installation and is located as shown in FIG. 1 in a position connecting with one of the passages 18 which in turn is connected with the bleeder channel 19.

In the operation of this deicer boot an inflating means such as air is injected through the air inlet opening 26 causing the top ply 14 and sheet member 15 to distend outwardly between the stitches 17 as shown in FIG. 4. This distension shatters the ice layer which may have formed on the sheet member 15 and the airflow past the deicer boot 10 blows the ice particles away from this surface. It is noted that with this construction, manifolds are not necessary since the inflating medium may flow between the passages 18 around the stitches 17. This is what is known as a sewn deicer construction. Rapid deflation of the deicer boot is then obtained by opening the air inlet and outlet opening 26 whereupon the air in the passages 18 will be urged to the trailing edges 11 and 12 where'it will be taken through the channel 19 to the air inlet and outlet opening. The upright fibers 24 located in the bleeder channel 19 prevent collapse of the channel and rapid flow of the air out of the deicer boot to provide the maximum efficiency of operation.

In the manufacture of the deicer boot 10 described heretofore, the parts which are not sewn together are cemented together and may be vulcanized to provide a unitary structure which will withstand the severe operating conditions found on the airfoil of an aircraft and especially on the leading edge where the deicer boot is mounted.

I claim:

1. An inflatable deicer boot for mounting on an airfoil comprising a series of passages extending longitudinally of said airfoil which can be selectively inflated and deflated to break up a formation of ice on said airfoil, said boot having a longitudinally extending trailing edge, a bleeder channel in said trailing edge, a plurality of closely spaced openings in said channel for communication with at least one of said passages over substantially the length of said boot for flow of the inflating medium away from said passages and longitudinally of said boot during deflation of said boot, said boot having an inner ply adapted for attachment to said airfoil and an outer ply of distensible material overlying said inner ply and said passages, a reinforcing member extending from said trailing edge over said channel and into the edge of said outer ply, and said channel having opposing faces held apart by a plurality of closely spaced elongated elements extending from one face of said channel towards the other face to hold the channel open for rapid deflation and collapse of said passages to break up ice forming on said airfoil.

2. An inflatable deicer boot according to claim 1 wherein said closely spaced elements are stiff fibers projecting outwardly from a fabric strip mounted in said channel.

3. An inflatable deicer boot according to claim 2 wherein said boot has an opening in the face thereof, said reinforcing member extending around and on both sides of said channel in the area of said opening and said channel exte ids along the traii i edge of said boot ad acent sai opening to provr flow along said trailing edge between separated areas of said boot for rapid deflation of all areas and collapse of said passages to break up ice forming on said airfoil.

4. An inflatable deicer boot according to claim 2 wherein said boot has two trailing edges with bleeder channels in both of said trailing edges.

UNIT D STATES PATENT OFFICE CERTIFICATE OF CORRECTION I Patent 3,690,601 1 Dated September 12, 1972 Inventor(s) LOWELL W. ROEMKEI It is certified that error appears in the above-identified patent I and that said Letters Patent are hereby corrected as shown below:

Please show that this patent has been assigned to The B.F.Go'odrich Company, New York, N. Y.

Signed and sealed this 8th day of May 1973.

(SEAL) Attest:

- ROBERT GOTTSCHALK Attesting Officer F ORM PO-] 050 (0-69) USCOMM-DC 60376-P69 s u.s. GOVERNMENT PRINTING OFFICE: I969 o;si-3a4 

1. An inflatable deicer boot for mounting on an airfoil comprising a series of passages extending longitudinally of said airfoil which can be selectively inflated and deflated to break up a formation of ice on said airfoil, said boot having a longitudinally extending trailing edge, a bleeder channel in said trailing edge, a plurality of closely spaced openings in said channel for communication with at least one of said passages over substantially the length of said boot for flow of the inflating medium away from said passages and longitudinally of said boot during deflation of said boot, said boot having an inner ply adapted for attachment to said airfoil and an outer ply of distensible material overlying said inner ply and said passages, a reinforcing member extending from said trailing edge over said channel and into the edge of said outer ply, and said channel having opposing faces held apart by a plurality of closely spaced elongated elements extending from one face of said channel towards the other face to hold the channel open for rapid deflation and collapse of said passages to break up ice forming on said airfoil.
 2. An inflatable deicer boot according to claim 1 wherein said closely spaced elements are stiff fibers projecting outwardly from a fabric strip mounted in said channel.
 3. An inflatable deicer boot according to claim 2 wherein said boot has an opening in the face thereof, said reinforcing member extending around and on both sides of said channel in the area of said opening and said channel extends along the trailing edge of said boot adjacent said opening to provide for continuous flow along said trailing edge between separated areas of said boot for rapid deflation of all areas and collapse of said passages to break up ice forming on said airfoil.
 4. An inflatable deicer boot according to claim 2 wherein said boot has two trailing edges with bleeder channels in both of said trailing edges. 